Sub-region lag - all mobs, most actions

In one sub-region (1/16 of a region):
everything slow - mobs move/take hit/water bob at 1/4, blocks mine at 1/4 leaving ghosts that need to be re-mined, oven smelts at 1/4 speed, daytime/ nighttime at 1/4, crops grow at 1/4.
errors in fishing and boating - host will skip all over the place.
Host moves and acts in real-time, though.
But, once i leave that 1/16 region - all other regions everything fine.